/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University.  All rights reserved.
 * 
 *
 *Redistribution and use in source and binary forms, with or without 
 *modification, are permitted provided that the following conditions are met:
 *
 *1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license;
 *2) All redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the disclaimer listed in this license in
 * the documentation and/or other materials provided with the distribution;
 *3) Any documentation included with all redistributions must include the 
 * following acknowledgement:
 *
 *"This product includes software developed by the Community Grids Lab. For 
 * further information contact the Community Grids Lab at 
 * http://communitygrids.iu.edu/."
 *
 * Alternatively, this acknowledgement may appear in the software itself, and 
 * wherever such third-party acknowledgments normally appear.
 * 
 *4) The name Indiana University or Community Grids Lab or NaradaBrokering, 
 * shall not be used to endorse or promote products derived from this software 
 * without prior written permission from Indiana University.  For written 
 * permission, please contact the Advanced Research and Technology Institute 
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202.
 *5) Products derived from this software may not be called NaradaBrokering, 
 * nor may Indiana University or Community Grids Lab or NaradaBrokering appear
 * in their name, without prior written permission of ARTI.
 * 
 *
 * Indiana University provides no reassurances that the source code provided 
 * does not infringe the patent or any other intellectual property rights of 
 * any other entity.  Indiana University disclaims any liability to any 
 * recipient for claims brought by any other entity based on infringement of 
 * intellectual property rights or otherwise.  
 *
 *LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO 
 *WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 *NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF 
 *INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS. 
 *INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS", 
 *"VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.  
 *LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR 
 *ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION 
 *GENERATED USING SOFTWARE.
 */
package cgl.narada.transport.threadpool;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Iterator;

import cgl.narada.transport.TransportDebugFlags;
import cgl.narada.transport.TransportException;

/**
   This is used by the broker process to set up a ServerSocket at the port 
   number that is specified. This class accepts connections from clients and
   and is responsible for passing inbound connection information to the 
   PoolTCPLinkFactory, which then registers the inbound link to its list of 
   managed links.

   @author Shrideep Pallickara
   $Revision $
   $Date$
*/

public class PoolTCPServerThread extends Thread 
  implements TransportDebugFlags {
  
  /** The server socket which is set up when the PoolTCP link factory loads its
      services */
  private ServerSocketChannel ssc;
  
  /* A handle to the PoolTCP link factory */
  private PoolTCPLinkFactory pooltcpFactory;
  
  private String moduleName="PoolTCPServerThread: ";
  private int port;
  private Selector acceptSelector;

  public PoolTCPServerThread(int portNum) throws TransportException{
    port = portNum;
    createServerSocket(portNum);
  }
  
  public PoolTCPServerThread(int portNum, PoolTCPLinkFactory pooltcpFactory) 
    throws TransportException {
    port = portNum;
    if (pooltcpFactory == null) {
      throw new TransportException(moduleName + 
				   "The PoolTCPLinkFactory is null");
    }
    this.pooltcpFactory = pooltcpFactory;
    createServerSocket(portNum);
  } 
  
  private void createServerSocket(int portNum) throws TransportException {
     try {
      ssc = ServerSocketChannel.open();
      ssc.socket().bind(new InetSocketAddress(portNum));
      
      ssc.configureBlocking(false);
      acceptSelector = Selector.open();
      ssc.register(acceptSelector, SelectionKey.OP_ACCEPT);
      
      if (PoolTCPServerThread_Debug)
	System.out.println(moduleName + "TCP ServerSocket created on port [" 
			   + portNum + "]");
    } catch (Exception e) {
      String errorInfo = moduleName+ "Couldn't create TCPServerSocket on " +
	"port [" + portNum + "] " + e.toString();
      
      if (PoolTCPServerThread_Debug) {
	System.out.println(errorInfo);
	e.printStackTrace();
      }
      throw new TransportException(errorInfo);
    }/*end try-catch */
     
  }
  
  public void closeServerSocket() {
    System.out.println(moduleName + "Closing PoolTCP ServeSocket on port [" +
		       port + "]");
    try {
      ssc.close();
    }  catch (IOException ioe) {
      System.out.println(moduleName + "Problems closing serverSocket " + ioe);
      if (PoolTCPServerThread_Debug) {
	ioe.printStackTrace();
      }
    }
  }

  
  
  public void run() {
    if (PoolTCPServerThread_Debug) {
      System.out.println(moduleName + "Starting PoolTCPServerThread");
    }
    try {
      while (true) {
	int status = acceptSelector.select();
	
	if (status == 0) {
	  continue;
	}
	
	Iterator it = acceptSelector.selectedKeys().iterator();

	while(it.hasNext()) {
	  SelectionKey key = (SelectionKey) it.next();
	  
	  if (key.isAcceptable()) {
	    SocketChannel sc = ssc.accept();
	    pooltcpFactory.handleInboundPoolTCPLinkRequest(sc);
	  }
	  // Remove key 
	  it.remove();
	}
      } /*end -while */
    } catch (Exception ioe) {
      System.out.println(moduleName + "run() " + ioe);
    }/*end try-catch */
    System.out.println(moduleName + "Thread shutting down");
  }
  
  public static void main(String[] args) {
    if (args.length != 1) {
      System.out.println("Usage: " + 
			 "java cgl.narada.transport.threadpool." +
			 "PoolTCPServerThread <port-num>");
      System.exit(0);
    }
    
    try {
      PoolTCPServerThread serverThread = 
	new PoolTCPServerThread(Integer.parseInt(args[0]));
      serverThread.start();
      serverThread.closeServerSocket();
    } catch (TransportException transEx) {
      System.out.println(transEx);
    } /*end try-catch */
  }

}






